1. Field of the Invention
The present invention relates to an image forming system where maintenance can be partially executed during execution of an image forming process, a maintenance method applied thereto, and a program for ca using a computer to implement the maintenance method.
2. Description of the Related Art
Conventionally, there has been provided an image forming system in which the main unit of an image forming apparatus, such as a copier, is connected to a post-processing apparatus, such as a finisher, to thereby realize a variety of post-processing required by users, such as a bundle discharging process, a stitching process, a folding process, or a binding process. The post processing apparatus normally executes a single type of post processing, with the post-processing apparatus required by the user being selected from a variety of types of post processing apparatuses and connected to an image forming apparatus.
With this kind of image forming system, external covers respectively provided on the image forming apparatus and the post-processing apparatus are opened or removed when a user clears a jam or a serviceman carries out maintenance such as replacement of parts, adjustments, or cleaning.
The external cover of the image forming apparatus completely covers a conveying path provided for a process that forms an image on a sheet fed from any of sheet cassettes, a conveying path provided for a process that discharges the sheet on which the image has been formed outside the apparatus, and a conveying path provided for a process where in double-sided recording mode, a sheet that has been reversed after single-sided image formation is conveyed to an image forming section once again. Accordingly, by merely opening or removing the external cover, it is possible to access all of the positions required for clearing a jam or carrying out maintenance. In the post-processing apparatus as well, the external cover is provided so as to cover all of the conveying paths inside the apparatus.
The external covers provided on the image forming apparatus and the post-processing apparatus are not opened or removed during a normal image forming operation, and should be opened or removed during a non-operational state in which a normal image forming operation is not carried out, such as maintenance or when a jam is cleared.
For this reason, as disclosed in Japanese Laid-Open Patent Publications (Kokai) No. H11-052813 and No. H07-244452, for example, when either of the external covers has been opened or removed during a normal image forming operation, it is assumed that an abnormal state has occurred and all operations of the image forming apparatus and the post-processing apparatus are stopped.
Meanwhile, to enable a single image forming system to execute a plurality of types of post-processing required by users, such as the bundle discharging process, the stitching process, the folding process, and the binding process, a plurality of post-processing apparatuses that are dedicated to the respective types of post-processing are connected in series to an image forming apparatus.
On the other hand, in the image forming apparatus and the post-processing apparatus, it is necessary to perform maintenance such as replacement of parts, adjustments, and cleaning whenever a predetermined number of sheets have been processed. However, in this kind of image forming system, all sheets do not pass the same conveying path. That is, the conveying path on which sheets are conveyed differs in accordance with user settings. In the case of the image forming apparatus main unit, for example, the conveying path on which sheets pass differs between single-sided recording mode and double-sided recording mode, and in the case of a plurality of post-processing apparatuses connected in series, the number of conveyed sheets that pass the conveying paths of the respective post-processing apparatuses differs between stitching mode, folding mode, and binding mode. For this reason, the timing of maintenance differs between the respective conveying paths of the image forming apparatus and the respective post-processing apparatuses in the image forming system. Also, out of the types of maintenance, in the case of replacement of parts for example, since the parts composing the conveying paths themselves wear out after respectively different numbers of sheets have passed, even if the same number of sheets have passed each of the conveying paths, the timing at which the parts on such conveying path are replaced differs.
However, the conventional image forming systems described above are designed so that if one of the external covers is opened or removed to perform maintenance, the operation of the entire image forming system is halted. Also, when a plurality of post-processing apparatuses are connected in series, to perform maintenance without stopping the operation of the entire image forming system, it is necessary to detach the post-processing apparatus to be subjected to maintenance from the image forming system and to repeat an initialization operation for causing a controller that controls the entire image forming system to recognize the connection state of the post-processing apparatuses after the detachment.